>> i heard of it. it's like -- you put some -- you put a tape in it, and then you click it and you listen to it. >> a cassette tape? like, something for music. >> oh, it's, like, you play music on it, and it's like -- they used it in like the '90s and '80s before cds came out. i actually wanted to start collecting some. >> back in the 1970s through the 1990s, cassette tapes were very popular. magnetic tape ran between two spools encased in a plastic shell. cassettes could come pre-recorded with, let's say, music on them, or they could be blank, allowing you to record what you want. [ mid-tempo music plays ] cassettes were bulky, and the tape was easily damaged. little wonder that they went the way of the dinosaur when cds and then mp3s were invented. with "speak of the week," i'm tatyana. >> in some schools, you won't see students carrying textbooks or notebooks or even pens and pencils. instead, you'll see ipads.